Dynamic Binary Modification Tools Form A Software Layer Between A Running Application And The Underlying Operating System, Providing The Powerful Opportunity To Inspect And Potentially Modify Every User-level Guest Application Instruction That Executes. Toolkits Built Upon This Technology Have Enabled Computer Architects To Build Powerful Simulators And Emulators For Design-space Exploration, Compiler Writers To Analyze And Debug The Code Generated By Their Compilers, Software Developers To Fully Explore The Features, Bottlenecks, And Performance Of Their Software, And Even End-users To Extend The Functionality Of Proprietary Software Running On Their Computers. Several Dynamic Binary Modification Systems Are Freely Available Today That Place This Power Into The Hands Of The End User.